Field of the Invention
The invention disclosed in this specification relates to a comparator circuit having an offset automatic correction technique between a plurality of comparators, and a power supply control IC and a switching power supply device using the comparator circuit.
Description of Related Art
Conventionally, there is known a comparator that can selectively use a plurality of comparators having different circuit characteristics in accordance with a state.
However, in the conventional comparator circuit, if input offsets of the comparators are largely different from each other, logic switching timing of a comparison signal differs even if the same input signal is compared with the same reference voltage. As a result, there is a problem that an output accuracy of the entire comparator circuit is deteriorated.
Further, an offset adjusting method disclosed in JP-A-2010-35140 includes comparing an output of a first comparator with an output of a second comparator, and setting offset amounts having opposite polarities to the comparators in accordance with the comparison result, and is different from the present invention in the essential structure.